[CRYPTO] digest: Add alignment handling

Some hash modules load/store data words directly.  The digest layer
should pass properly aligned buffer to update()/final() method.  This
patch also add cra_alignmask to some hash modules.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 27 insertions, 15 deletions

diff --git a/crypto/digest.c b/crypto/digest.c
index d9b6ac9dbf8..062d0a5a2c8 100644
--- a/crypto/digest.c
+++ b/crypto/digest.c
@@ -27,6 +27,7 @@ static void update(struct crypto_tfm *tfm,
                    struct scatterlist *sg, unsigned int nsg)
 {
         unsigned int i;
+        unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
 
         for (i = 0; i < nsg; i++) {
 
@@ -38,12 +39,24 @@ static void update(struct crypto_tfm *tfm,
                         unsigned int bytes_from_page = min(l, ((unsigned int)
                                                            (PAGE_SIZE)) - 
                                                            offset);
-                        char *p = crypto_kmap(pg, 0) + offset;
+                        char *src = crypto_kmap(pg, 0);
+                        char *p = src + offset;
 
+                        if (unlikely(offset & alignmask)) {
+                                unsigned int bytes =
+                                        alignmask + 1 - (offset & alignmask);
+                                bytes = min(bytes, bytes_from_page);
+                                tfm->__crt_alg->cra_digest.dia_update
+                                                (crypto_tfm_ctx(tfm), p,
+                                                 bytes);
+                                p += bytes;
+                                bytes_from_page -= bytes;
+                                l -= bytes;
+                        }
                         tfm->__crt_alg->cra_digest.dia_update
                                         (crypto_tfm_ctx(tfm), p,
                                          bytes_from_page);
-                        crypto_kunmap(p, 0);
+                        crypto_kunmap(src, 0);
                         crypto_yield(tfm);
                         offset = 0;
                         pg++;
@@ -54,7 +67,15 @@ static void update(struct crypto_tfm *tfm,
 
 static void final(struct crypto_tfm *tfm, u8 *out)
 {
-        tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
+        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+        if (unlikely((unsigned long)out & alignmask)) {
+                unsigned int size = crypto_tfm_alg_digestsize(tfm);
+                u8 buffer[size + alignmask];
+                u8 *dst = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+                tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), dst);
+                memcpy(out, dst, size);
+        } else
+                tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
 }
 
 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
@@ -69,18 +90,9 @@ static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 static void digest(struct crypto_tfm *tfm,
                    struct scatterlist *sg, unsigned int nsg, u8 *out)
 {
-        unsigned int i;
-
-        tfm->crt_digest.dit_init(tfm);
-                
-        for (i = 0; i < nsg; i++) {
-                char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
-                tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
-                                                      p, sg[i].length);
-                crypto_kunmap(p, 0);
-                crypto_yield(tfm);
-        }
-        crypto_digest_final(tfm, out);
+        init(tfm);
+        update(tfm, sg, nsg);
+        final(tfm, out);
 }
 
 int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)